With his party trailing third behind Labour and the UK Independence Party in polls for the Euro-elections on May 22, Mr Cameron denounced Nigel Farage’s party as “all talk and no delivery” and dismissed Labour as “all short-term gimmicks and no long-term plan”.
Only the Conservatives’ economic plan can maintain the “great British revival” seen in recent months, which have seen the UK economy growing faster than most of the developed world and achieving higher employment rates than the USA, he said.
And he argued that only a Conservative-led Government can deliver the EU referendum which he has promised by the end of 2017, repeating his pledge that he will not serve as Prime Minister in any coalition administration which fails to uphold this commitment.
Launching the Tory campaign in Staffordshire, Mr Cameron took aim at his rivals: “Frankly I don’t need to discredit Ukip – they do a good enough job themselves. Their own leader admits they ‘cannot change a thing in Brussels’.
“This is who we’re up against: Labour – all short-term gimmicks and no long-term plan. Ukip – all talk and no delivery.
“The choice is clear: If you want a serious party with a credible long-term plan and a party that’s delivering on that plan, then you only have one choice: you have got to vote Conservative.”
Ahead of polls taking place in local councils across England, the Prime Minister said that the effects of recovery were being seen in all parts of the country.
“Britain is coming back,” he said. “We came through the Great Recession together. We are building the Great British revival together.
“And all this didn’t just happen. The economic pendulum didn’t just swing our way. It’s happening because of the people in this country who worked their hearts out, the businesses that hung on through the hard times and yes – it happened because this is a Government with a long-term economic plan to secure Britain’s future.”
The Tory plan for Europe had “three words at its heart – Britain’s national interest”, he said.
“I have a track record of delivery – and believe me, whatever it takes, I will deliver this in-out referendum. Labour won’t. Ukip can’t. I will.
“Earlier this week I made clear I would not lead a Government that either could not or did not deliver an in-out referendum.
“Let me be absolutely clear. The British people need to have their say on our membership of the EU.
“For me this is a fundamental principle. And I would not be Prime Minister of a government unless we could carry out our pledge of an in-out referendum. Because the British people deserve their say. And I will make sure they get it.”
A YouGov poll at the weekend put the Conservatives in third place in the Euro-elections, with 19 per cent support, well behind Ukip on 31 per cent and Labour on 28 per cent.
For Labour, shadow Cabinet Office minister Michael Dugher – the MP for Barnsley East – said: “David Cameron is obsessing about Ukip rather than the cost-of-living crisis faced by British families.
“Once again, this is weakness not leadership. David Cameron is banging on about Europe, putting party interest before the national interest.
“With things getting harder, the big question at this election is who will best stand up for hard-working families, but David Cameron is in the pocket of the privileged few.”